Abstract:An electronic microarray has been used to carry out directed self-assembly of higher order 3D structures from biotin/streptavidin, DNA and enzyme derivatized nanoparticles. Structures with up to fifty layers of alternating biotin and streptavidin, DNA and enzyme nanoparticles were fabricated using a 400 site CMOS microarray system. In this process, reconfigurable electric fields produced by the microarray were used to rapidly transport, concentrate and accelerate the binding of 40 and/or 200nm nanometer bio-derivatized nanoparticles to selected sites on the microarray. The nanoparticle layering process takes less than one minute per layer. The nanoparticle addressing/binding process was monitored by changes in fluorescence intensity as each nanoparticle layer was deposited. The final multilayered 3-D structures are about two microns in thickness and 50 microns in diameter. Most recently we have successfully fabricated enzyme-nanoparticle layers with streptavidin-alkaline phosphatase, glucose oxidase-avidin, and streptavidin-HRP. Up to 47 layers were addressed with 200nm nanoparticles and enzyme activity was retained in the assembled structure. This work represents a unique example of combining “top-down” and “bottom-up” technologies into a novel nanofabrication process. Such a process will be useful for the hierarchal assembly of 3D nano, micro, and macrostructures for a variety of electronic/photonic, nanomaterials, energy and biosensor applications.